Segmentation of progressive multifocal leukoencephalopathy lesions in fluid-attenuated inversion recovery magnetic resonance imaging.

BACKGROUND AND PURPOSE: The authors compared the reproducibility of a manual and a semiautomated technique for the quantitation of white-matter lesions in magnetic resonance imaging (MRI).

METHODS

Volumes of white-matter lesions were determined using fluid-attenuated inversion recovery MRI in 23 AIDS patients with progressive multifocal leukoencephalopathy. Manual outlining was compared to an automated method based on region growing and adaptive thresholding.

RESULTS

Lesion volumes from the 2 methods correlated well (61 lesions, r = 0.99, P < 10(-4)), although the volumes differed substantially (12.8% +/- 13.7%). Interscan, intrasubject reproducibility was better for the automated than the manual method (2.9% +/- 3.2% vs 12.4% +/- 16.2% volume difference, P = .02).

CONCLUSION

The automated algorithm appeared more reproducible, which renders it superior to the manual method for longitudinal studies.